A wide variety of machines for paving and compacting asphalt or other paving material have been used for decades. A conventional approach for paving a surface such as a road or parking lot is to distribute hot paving material onto a prepared bed of gravel and/or soil with a paving machine, then to follow the paving machine with one or more compactor machines to compact the material to a desired density and obtain an acceptable surface finish. Completing compaction can often require multiple passes across the mat with a compactor machine.
One such compactor machine is a drum-type compactor having one or more drums adapted to compact the particular surface over which the compactor is being driven. In order to compact the surface, the drum-type compactor may include a drum assembly having a vibratory mechanism that includes inner and outer eccentric weights arranged on rotatable shafts situated within the drum. Both amplitude and frequency of vibration may be controlled to establish degree of compaction.
Another type of compactor machine is a pneumatic wheel roller-style compactor, which is partially dependent upon tire pressure for achieving effective compaction. For successful operation of the pneumatic compactor, the ground contact pressures should be managed in accordance with compaction surface type. Oftentimes, an operator estimates a contact pressure based upon weight of the machine, air pressure of the tires, and compaction conditions in accordance with a chart or other guidelines provided by the machine manufacturer.
Paving material is typically comprised of viscous hydrocarbons, and gravel or the like. The paving material is deposited at a relatively high temperature, and cools to harden into a finished product. It is well known that the hot, viscous hydrocarbon constituents of paving material can stick to machinery. Where paving material sticks to ground contacting parts of the machinery, such as the rotating drums or tires of compactors, the quality of the paving material mat can suffer, and continued operation of the machinery can itself be compromised. This problem is especially noted when the drums or tires of compactors are not at an elevated temperature. For example, if a pneumatic compactor is not warmed-up (i.e., operated) off-site prior to compaction, the tires are too cool and asphalt will stick to the tires, thereby adversely affecting the functioning of the machine and the resulting mat. Recognizing this phenomenon, engineers have developed several ways to address asphalt sticking problems over the years.
For example, systems are available specifically for pneumatic compactors to minimize the amount of asphalt pickup by the tires. One method is to spray water or an emulsion onto the tires to remove the asphalt pickup. Another method involves heating the tires in advance of operation of the pneumatic compactor. Heat retaining tire skirts are also employed to enclose the air surrounding the tires helping to maintain this air at a relatively warm temperature once the tires are heated by operation or by a heating element.
While such tire skirts are effective at maintaining a heated environment for the tires, and thereby reduce asphalt pickup, tire skirts generally block the machine operator's view of the tires. As such, the operator is unable to see where the tires are contacting the ground or mat. Likewise, the operator is unable to see whether the tires are picking up asphalt and therefore marking the mat. Accordingly, it would be beneficial to provide a system for maintaining a heated environment while allowing observation and inspection of the tires by the machine operator.